This invention relates to a coke oven battery which is regeneratively heated by the combustion of lean gas and air in a heating chamber disposed between two coking chambers and divided into vertically-extending upgoing and downgoing heating flues by header walls, and more particularly, to such a coke oven battery wherein the header walls are coupled to air supply means and alternate along the row of heating flues with header walls coupled to lean gas supply means.
In coke ovens of this general type, special problems arise which relate inter alia to the difficulty of achieving the uniform vertical heating of the coal charge in the coke oven chambers. In this regard, coke ovens have been constructed in a manner whereby fuel gas which is not preheated is supplied at the sole of the heating flues and the air is supplied through header flues having a plurality of exit ports disposed at different heights such that the size of the ports increase in the upward direction.
It is also known in the prior art to supply a coke oven battery with lean gas through header flues having vertically-graded exits. Part of the heating gas together with the total quantity of air for combustion is supplied with a change of draught at the base of the upgoing heating flues while all the header flues are constantly fed with lean gas. The bottom ends of the heating flues and along the greater part of these flues, therefore, have a constant excess of air which is available for combustion with the lean gas supplied through the header flues even in the downgoing heating flue.
Recent efforts have been made to insure that the smoke gases which are discharged from the heating system of coke ovens have the lowest possible content of nitrogen oxides. The present invention is addressed to solving this problem and more particularly by providing an arrangement of parts which insures that the presence of nitrogen contained in the combustion air is at a minimum, particularly in the zones of maximum heat development in such a way that there is the least possible amount of oxygen supplied which is not immediately combined with the constituents of the fuel gas. The other long-standing problem of heating the charge of coal in the oven chambers as uniformly as possible over its entire height is also solved according to the present invention.